Simplify the following expression: $k = \dfrac{1}{4p} - \dfrac{7}{6p}$
Answer: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4p$ and $6p$ $\lcm(4p, 6p) = 12p$ $ k = \dfrac{3}{3} \cdot \dfrac{1}{4p} - \dfrac{2}{2} \cdot \dfrac{7}{6p} $ $k = \dfrac{3}{12p} - \dfrac{14}{12p}$ $k = \dfrac{3 -14}{12p}$ $k = \dfrac{-11}{12p}$